tools: align locale diagnostics and generate native language names

preview/index.html

@@ -482,34 +482,8 @@ function fillSelect(id, entries, selected) {
   select.value=selected;
 }
 
-// Stable native names also cover browsers with incomplete ICU locale data.
-const LOCALE_NAMES = {
-  'cs-CZ':'čeština (Česko)', 'de-DE':'Deutsch (Deutschland)',
-  'el-GR':'Ελληνικά (Ελλάδα)', 'en-US':'English (United States)',
-  'es-ES':'español (España)', 'fa-IR':'فارسی (ایران)',
-  'fi-FI':'suomi (Suomi)', 'fr-FR':'français (France)',
-  'ga-IE':'Gaeilge (Éire)', 'hu-HU':'magyar (Magyarország)',
-  'id-ID':'Indonesia (Indonesia)', 'is-IS':'íslenska (Ísland)',
-  'it-IT':'italiano (Italia)', 'ja-JP':'日本語 (日本)',
-  'ko-KR':'한국어 (대한민국)', 'lv-LV':'latviešu (Latvija)',
-  'nl-NL':'Nederlands (Nederland)', 'pl-PL':'polski (Polska)',
-  'pt-BR':'português (Brasil)', 'pt-PT':'português (Portugal)',
-  'ru-RU':'русский (Россия)', 'si-LK':'සිංහල (ශ්‍රී ලංකාව)',
-  'sk-SK':'slovenčina (Slovensko)',
-  'sv-SE':'svenska (Sverige)', 'tr-TR':'Türkçe (Türkiye)',
-  'uk-UA':'українська (Україна)', 'zh-CN':'中文 (简体，中国)',
-  'zh-TW':'中文 (繁體，台灣)'
-};
-
 function localeLabel(locale) {
-  let name = LOCALE_NAMES[locale];
-  if (!name) {
-    try {
-      if (Intl.DisplayNames.supportedLocalesOf([locale]).length) {
-        name = new Intl.DisplayNames([locale], {type:'language', fallback:'none'}).of(locale);
-      }
-    } catch (_) { /* Unknown languages remain selectable by their locale code. */ }
-  }
+  const name = manifest?.language_names?.[locale];
   return name && name !== locale ? locale + ' — ' + name : locale;
 }